This invention relates to deflectable catheters.
In order to facilitate the advancement of catheters through a body lumen (e.g., an artery) deflectable catheters have been developed. The simultaneous application of torque at the proximal end of the catheter and the ability to selectively deflect the distal tip of the catheter in a desired direction permits the physician to adjust the direction of advancement of the distal end of the catheter, as well as to position the distal portion of the catheter during e.g., an electrophysiology procedure.
A surgeon may manipulate the proximal end of the catheter to guide the catheter through a patient's vasculature. The deflection of the distal tip is typically provided by a pull wire that is attached at the distal end of the catheter and extends to a control handle that controls the application of tension on the pull wire.
In electrophysiology catheter designs it is critically important to have sufficient flexibility in the catheter shaft so that when the catheter is advanced through a blood vessel the catheter may follow the inherent curvature of the vessel without puncturing the vessel wall.
In order to maneuver around turns and bends in the vasculature, the surgeon observes the catheter fluoroscopically, and selectively deflects the tip and rotates the proximal end of the catheter shaft. However, the ability to control the precise position of the distal end of the catheter depends on the fidelity of the catheter's transmission of the forces exerted at the proximal end to the distal tip.
Without high fidelity torque transmission, the surgeon is unable to control the catheter tip. At best, this only delays an operating procedure, and at worst this may cause the distal tip of the catheter to cause trauma to a patient.